No. A way to block all connections except localhost for the custom TBB.
2 posts were split to a new topic: Tor Browser 9 - lockPref - false are ignored in my mozilla.cfg
A lot progress on this was made but this thread was not updated.
There is an i2pbrowser wrapper script in tb-starter package. Installed by default in Whonix even in stable repository. But I am not sure it’s functional or maintained. No idea if still functional in Tor Browser 9. I don’t maintain it.
Probably best discussed in this thread: